diff --git a/lib/multi.c b/lib/multi.c
index d5c6a3e83b..bf0e89ae6a 100644
--- a/lib/multi.c
+++ b/lib/multi.c
@@ -59,7 +59,9 @@
 #define CURL_SOCKET_HASH_TABLE_SIZE 911
 #endif
 
+#ifndef CURL_CONNECTION_HASH_SIZE
 #define CURL_CONNECTION_HASH_SIZE 97
+#endif
 
 #define CURL_MULTI_HANDLE 0x000bab1e